The present invention relates to a vehicular power unit arrangement structure and a method and, more particularly, to a vehicular power unit arrangement structure and its related method which enable a falling behavior of the power unit during a frontal collision of the vehicle to be stably controlled.
Japanese Patent Application Laid-Open Publication No. H9-240291 discloses a vehicular power unit arrangement structure. Such a structure is comprised of right and left downwardly and curvedly contoured sub-frames that are disposed beneath a power-unit mounting room. A lower portion of the power unit is mounted to the right and left sub-frames, with an upper portion of the power unit being mounted to side-members which are disposed above the power-unit mounting room at right and left sides thereof in a way such that the power unit is ready to be released upon receipt of vertical load beyond a given value. That is, with such a structure, downward bending operation of the sub-frame during the frontal collision of the vehicle permits the power unit to fall down.
However, in such a structure, extensive studies undertaken by the present inventors have revealed that the presence of the curvedly contoured regions of the sub-frames tends to cause the sub-frame to bend in a wide range of an unstable bending region when the sub-frame is subjected to load exerted during the frontal collision of the vehicle. Thus, the need for further improvement in control of the amount of dropping of the power unit would be apparent.
The present invention has been completed with the above view and it is therefore an object of the present invention to provide a vehicular power unit arrangement structure and its related method which is enable to stably control a falling behavior of a power unit during a frontal collision of a vehicle while enabling the power unit to suitably get into an area beneath a vehicular compartment.
According to one aspect of the present invention, a power unit arrangement structure for a vehicle, which has a mounting room partitioned in front of a vehicular compartment for receiving a power unit, comprises: a side-member extending in a fore and aft direction of a mounting room and enabled to achieve buckling deformation in the fore and aft direction during a frontal collision; a sub-frame extending in the mounting room along the fore and aft direction at an area below the side-member; a mount member having respective an insulating function and permitting a power unit to be supported with the side-member, the mount member being capable of tearing in response to relative movement of the side-member and the power unit in the fore and aft direction during the frontal collision; a bent portion disposed at a substantially intermediate portion of the sub-frame in the fore and aft direction and having a downwardly bent configuration; and a connecting member connecting a lower portion of the power unit to the sub-frame in the vicinity of the bent portion. The sub-frame has a part having a substantially V-shaped configuration having the bent portion in a side view.
In other words, in the present invention, a power unit arrangement structure for a vehicle, which has a mounting room partitioned in front of a vehicular compartment for receiving a power unit, comprises: a side-member extending in a fore and aft direction of a mounting room and enabled to achieve buckling deformation in the fore and aft direction during a frontal collision; a sub-frame extending in the mounting room along the fore and aft direction at an area below the side-member; a mount member having respective an insulating function and permitting a power unit to be supported with the side-member, the mount member being capable of tearing in response to relative movement of the side-member and the power unit in the fore and aft direction during the frontal collision; start point defining means, which is disposed at a substantially intermediate portion of the sub-frame along the fore and aft direction, for defining a start point to induce a downwardly convex deformation in the sub-frame during the frontal collision; and connecting means for connecting a lower portion of the power unit to the sub-frame in the vicinity of the bent portion. The sub-frame has a portion having a substantially V-shaped configuration in a side view.
Besides, in the present invention, a method of controlling a falling behavior of a power unit of a vehicle, which has a mounting room partitioned in front of a vehicular compartment for receiving the power unit, comprises: preparing a side-member extending in a fore and aft direction of a mounting room; preparing a sub-frame extending in the mounting room in the fore and aft direction at an area below the side-member, the sub-frame including a bent portion having a downwardly bent configuration formed at a substantially intermediate portion of the sub-frame along the fore and aft direction; preparing a mount member having insulating function and permitting a power unit to be supported with the side-member; preparing a connecting member connecting a lower portion of the power unit to a close proximity area of the bent portion of the sub-frame; causing the side-member to be subjected to buckling deformation in the fore and aft direction during a frontal collision; tearing the mount member in response to relative movement between the side-member and the power unit in the fore and aft direction during the frontal direction; and causing the sub-frame to be bent in downwardly convex configuration at a starting point provided by the bent portion during the frontal collision.
Other and further features, advantages, and benefits of the present invention will become more apparent from the following description taken in conjunction with the following drawings.